It is proposed to study the structural requirements of beta-adrenoceptor antagonists leading to cardioselectivity. To attain that aim a number of new beta-adrenoceptor antagonists will be synthesized with or without p-substituent in the l-aryloxy group and bearing 3-amino moiety closely related to homoveratryl in l-aryloxy-3-arylalkylamino-propan-2-ols. Their affinity to beta1 and beta2 adrenoceptors will be investigated using turkey erythrocyte membranes, rat ventricular muscle, rat lung membranes and guinea pig atrial, ventricular and tracheal strips.